The immigration issue was a key factor in Sunday's election, but the AfD also wants to halt arms supplies to Ukraine, as does the left-populist leader of the new party, Sarah Wagenknecht (BSW), which is expected to come in third in both states.
Ms. Wagenknecht shares similar views with the AfD on Ukraine, but refuses to join any coalition government with the party, making it unlikely that the far right will ever run Thuringia.
If the predictions are confirmed, the AfD is expected to win 30 seats in Thuringia's 88-seat state parliament, while the CDU is expected to win 24, leaving just one of the three parties forming the national government represented.
Chancellor Olaf Scholz's Social Democrats (SPD) are expected to win just seven seats, while the Greens and the liberal FDP are expected to win none.
With federal elections just over a year away, Sunday’s vote underscored the unpopularity of Germany’s ruling “traffic light” coalition, named for its party colors of red, yellow and green.
In the third eastern state, Brandenburg, where a vote is scheduled for three weeks later, the polls show the AfD ahead, but the Social Democrats and conservatives just a few points behind.
While Bjorn Höcke welcomed his party's victory to supporters in Erfurt, AfD opponents gathered outside the Thuringia state parliament.
Among them was Hannah, a local student, who said she was very worried about the consequences. “I think there are a lot of people who know that there was a Nazi policy, but they don't care. Germany has some kind of responsibility for this.”
The rise of Sarah Wagenknecht's populist party has had a direct impact on the Left Party, which won the last Thuringian state election but has now fallen to fourth place.
Bodo Ramelow, the Left Party premier in Thuringia, said the election campaign was marked by fear and that he was “fighting against the normalization of fascism”.
